A new high-performance, long-life gyroscope that serves as a
balancing "inner ear" for spacecraft has been licensed by NASA's
Jet Propulsion Laboratory, Pasadena, Calif., to the Hughes Space
and Communications Company, El Segundo, Calif.

Spacecraft require gyroscopes to maintain orientation in
flight. Gyroscopes determine changes in angular direction,
traditionally by virtue of a rapidly spinning, heavy mass.
Spinning mass gyroscopes, originally the gyroscopes of choice for
space applications, require lubrication and eventually wear out.
By contrast, the newly developed JPL/Hughes microgyro does not
have any specific life-limiting features. The resulting long life
of more than 15 years is a significant plus for space
applications.

Jointly developed by JPL and Hughes, this new gyroscope is
lighter, cheaper, higher-performing and less complex than its
conventional counterparts while uniquely designed for continuous
space operation. Its dimensions are 4 by 4 millimeters (0.16 by
0.16 inches)), smaller than a shirt button, and its weight is
less than one gram just under 0.03 ounces.

"This agreement typifies the type of cooperation between the
space program and industry that provides benefits back to
American business," said Merle McKenzie, manager of JPL's
Commercial Technology and Regional Economic Development Program.

Other gyroscopes designed for use in space use solid-state
technology -- that is, without any moving parts -- provide the
required long lifetime, but these instruments are very expensive,
power-hungry and bulky, weighing up to 20 pounds or more.

Current gyroscopes on a chip, only useful for some
terrestrial applications, can measure rotation at just over the
speed of the minute hand on a watch, but no slower, whereas the
newly licensed microgyro can measure rotation 30 times slower
than the hour hand. In the world of gyroscopes for space,
measurement of extremely slow rotation is highly desirable -- the
slower the better -- because the slowest of rotations can take a
spacecraft significantly off target over an extended period.

Unlike its microgyro counterparts, the JPL/Hughes instrument
features superior performance in both space and terrestrial
environments, making it a versatile, dual-use technology.

Like its current microgyro counterparts, the JPL/Hughes
version relies on measurement of vibrations. "The heart of the
instrument is a cloverleaf design that is tied down and vibrates
at a very high speed," said JPL's Dr. Tony Tang, engineering lead
for the development of the instrument. "We look for changes in
the vibration of a light piece of micro-machined silicon that has
no moving parts." The exclusive use of silicon helps to reduce
costs, since this durable material is now routinely used for
computer chips and it is thus more easily fabricated than other
materials.

The new microgyroscope, including its control electronics,
was created out of a technology cooperation agreement between
Hughes and JPL beginning in 1997. Hughes recently acquired
exclusive rights from the California Institute of Technology to
develop the microgyro for commercial space applications. Caltech
has the right to elect title to inventions developed at JPL under
its contract with NASA to manage JPL.